Hi, My 22 yo son has had a very itchy rash all over his body for quite a while. He was allergy tested, and went to a dermatologist. All have tried many things, and he changed his soap, shampoo and detergent. Still has rash. He has crohns, so he takes the following: entocort, pentasa, canasa suppositories, along with Adderall for his ADD. Any thoughts on what can cause this rash. He says sunlight helps it some. Thank you for any insight you may have. We re running out of ideas!